In this project we will develop novel imaging technology for quality control of tissue-engineered blood vessels (TEBV). Recent developments in the field of tissue engineering led to the development of completely biological living vascular graft that solves major problems associated with synthetic materials such as inflammation and infection. Since this type of vascular graft is not produced in large batches, but rather on a patient-to-patient basis, close monitoring of the development process is paramount. Unlike synthetic grafts, mechanical testing of duplicate grafts is very costly and not very reliable. Hence, there is growing demand for noninvasive methods to predict biomechanical properties. However, due to the novelty of the manufacturing process, no suitable imaging modalities exist. The purpose of this project is to develop and refine methods based on transillumination optical tomography (OT) and optical coherence tomography (OCT) for thin tissue samples (vascular grafts are 300 - 500 Lim thick), and relate the images to biomechanical properties. In this project, the OT and OCT scanners will be developed. This includes the acquisition control and the development of image reconstruction and enhancement algorithms. The goal is to achieve optimum signal-to-noise ratio at a resolution of 10 pm and short (5-20 minute) scanning times. Specialized bioreactors will be developed that allow to obtain images of the growing vessels inside the bioreactor without breaking sterility, allowing for routine examination. We will determine the capabilities of the new modalities in comparison with histology and with respect to biomechanical testing. The proposed OT and OCT imaging techniques are not limited to TEBV. Additional applications include conventional grafts as well as other tissue engineering products, such as artificial skin and cartilage. The results of this project will provide novel imaging methods that will accelerate the development and clinical availability of tissue engineering products. [unreadable] [unreadable]